Irene Oceanias: The lost trident of Poseidon (Book 1)

Irene Oceanias is the 15 year old daughter of Poseidon and his wife Queen Amphitrite Oceanias. Irene hasn't set foot on land since her the tragic death of her twin sister Princess Cassandra. But when several important ancient artifacts suddenly go missing, Irene's parents send her to Neptune Bay to live with of her loyal (half human, half mermaid) best friend Naomi Quinn and her mom Amy Quinn. Where she's enrolled as a foreign exchange student at Neptune Bay High School, in order to have a front to use to avoid raising any suspicion, while the two of them try and recover all the stolen artifacts. Perferably before any of the artifacts can fall into the wrong hands, but unfortunately for Irene and Naomi their not the only ones searching for the artifacts...